Advantages of a combined method of decalcification compared to EDTA

Decalcification of mineralized tissues is an essential step during tissue processing in the routine histopathology. The time required for complete decalcification, and the effect of decalcifier on cellular and tissue morphology are important parameters which influence the selection of decalcifying agents. In this study, we compared a decalcifying solution (ETDA) composed of both acid and chelating agents to a classical and well-known decalcifying agent (EDTA). To this purpose, the optic density of bone radiographs, residual calcium analysis, bone sample weight, and histological and immunohistochemical analysis were performed. Our data suggest that, similarly to EDTA, the ETDA solution completely removes the calcium ions from the samples enabling easy sectioning. However, unlike the EDTA, this agent takes much less time. Furthermore, both agents showed comparable decalcification efficacy, and similarly, they did not produce cellular, tissue or antigenicity impairments. Therefore, ETDA may be a suitable option when it is necessary an association between a rapid and complete removal of calcium minerals, and a suitable preservation of structure and antigenicity of tissues.